Manufacture of perforated bricks or blocks.



Patented January 1'7, 1905.

UNITED STATES PATENT OEEIcE.

ERNST Sllt lFFLER, OF ZURICH, SWITZERLAND.

MANUFACTURE OF PERFORATED BRICKS OR BLOCKS.

SPECIFICATION forming part of Letters Patent No. 780,138, dated January 17, 1905.

Application filed June 16, 1904. Serial No. 212,864.

To all whom it 'nuty concern.-

Be it known that I, ERNsT SrorELnR, a sub ject of the Emperor of Germany, residing at 72 Forchstrasse, Zurich, in the Republic of Switzerland, have invented new and useful Improvements in the Manufacture of Perforated Bricks or Blocks, of which the following is a specification. I

Thisinvention relates to the manufacture of perforated bricks or blocks.

It has heretofore only been possible to man ufacture perforated bricks or the like in die presses by employing bottom dies having movable pins or rods. The pins or rods on the top die can be rigid, since they are withdrawn from the molded article on raising the said die; but those on the bottom die must be movable, as otherwise it is not possible to Withdraw the molded article from the die. It has therefore been the practice to arrange for the pins or rods to be withdrawn after the molding or pressing operation is complete or before the bottom die is raised and the brick ejected from the mold. It is not possible to remove the molded brick from the mold-bottom until the pins are withdrawn into the die. Furthermore, the material to be molded easily passes into the guide-holes for the pins, and this, apart from the resulting wear of the parts, frequently so materially hinders the movement of the pins that the regular operation of the machine is prevented.

Now this invention has for its object to obviate these disadvantages, and to this end the molds, which are open at the top and bottom. The mold is first closed by a smooth bottom die, the corresponding smooth top die being at such a height above the mold that the latter can be filled. The top mold then approaches the lower mold and compresses the material until it adheres to the mold, when the dies are withdrawn, while the table is moved to the second position. The preliminary light compression by the smooth or plain dies possesses the advantage that the air inclosed in the raw material finds time and opportunity to escape before the final form is given to the brick. In the second position the partially-molded article is pressed between dies with rigid pins or rods. After this second-stage compression has been effected the dies, with the pins, recede,and the finished brick,which remains suspended in the mold, is moved by the rotation of the table to the third position. In this position the third stage of the operation takes placcthat is to say, the ejection or discharge die operates. The brick can be pressed out of the mold from below upward, in which case it must be lifted off or from above downward, in which case a conveyer-band is advanta geously provided for receiving the discharged l certained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is The herein-described method of manufacturing bricks, which consists in first lightly molding the bricks between plain-faced opposing dies in an lnclosing mold, whereby the compression of the material causes it to l moving both of said finishing and perforating adhere to the mold and the air inclosed in the dies, and then forcing the finished brick out material is largely expressed, then withdrawof the mold, substantially as described.

ing the plaindies, and finishing the molding ERNST STOFFLER of the brick While still held in the mold, With Wit opposing dies having rigid projections for S G BMDIWALD7 perforating or indenting the brick, then re F YV 

